Press structure

ABSTRACT

A mechanical press having a frame made up of a crown, front and back frame members beneath the crown, leg members beneath the frame members, and bridge members extending between the frame members at the bottom. A bed is moveably mounted in the space within the press frame at the bottom for adjustment toward and away from the crown. The crown carries counterrotating crankshafts connected by connecting rods with pistons slidably guided in cylinders in the head with a slide connected to the lower ends of the cylinders and being supported and guided solely thereby. An automatic feeding device is provided for feeding stock into the press and a belt drive is provided for driving the feeding device by a crankshaft of the press. Hydrostatic bearings are advantageously provided for the crankshaft bearing and for the pin portions of the crankshafts and between the cylinders and pistons that slide therein. The counterrotating crankshafts are provided with counter balancing means whereby the press is adapted to operate at high speeds.

tlnited States Patent Voorhees et all,

[ PRESS STRUCTURE [75] Inventors: John E. Voorhees, Sidney; Donald .1. Hemmelgarn, Minster, both of Ohio [73] Assignee: The Minster Machine Company,

Minster, Ohio 3 [22] Filed: Sept. 5, 1972 [21] App]. No.: 286,272

[52] US. Cl 72/455, 72/446, 72/450, 72/456 [51] Int. Cl B2lj 13/04 [58] Field of Search 72/455, 456, 450, 448, 72/446, 425, 419; 100/214; 308/5 R, 122, 9; 248/13 [56] References Cited UNITED STATES PATENTS 1,437,024 ll/1922 Schull 72/448 1,827,558 10/1931 Byerlein 72/446 1,883,513 10/1932 Borton l 72/455 1,960,166 5/1934 R0de..... 100/214 2,102,842 12/1937 Glasner. 72/450 2,652,770 9/1953 Wilkins 100/214 3,030,879 4/1962 Lasko 308/5 R 3,130,699 4/1964 Ward 72/450. 3,301,611 l/1967 Dunlap 308/5 R 3,464,654 9/1969 Kolesar 248/13 3,493,273 2/1970 Greenberg 308/122 3,549,216 12/1970 Sutyak 303/122 3,557,600 l/l97l Saito i 72/455 3,590,624 7/1971 PaX i 72/425 3,727,442 4/1973 Ridgway [111 3,858,432 [451 .lan."7,l975

FOREIGN PATENTS OR APPLICATIONS 435,985 11/1967 Primary Examiner-C. W. Lanham Assistant Examiner-Gene P. Crosby Attorney, Agent, or Firm-Albert L. Jeffers; Roger M. Rickert {57] ABSTRACT A mechanical press havinga frame made up of a crown, front and back frame members beneath the crown, leg members beneath the frame members, and bridge members extending between the frame members at the bottom. A bed is moveably mounted in the space within the press frame at the bottom for adjustment toward and away from the crown. The crown carries counterrotating crankshafts connected by connecting rods with pistons slidably guided in cylinders in the head with a slide connected to the lower ends of the cylinders and being supported and guided solely thereby. An automaticfeeding device is provided for feeding stock into the press and a belt drive is provided for driving the feeding device'by a crankshaft of the press. Hydrostatic bearings are advantageously provided for the crankshaft bearing and for the pin portions of the crankshafts and between the cylinders and pistons that slide therein. The counterrotating crankshafts are provided with counter balancing means whereby the press is adaptedto operate at high speeds.

35 Claims, 28 Drawing Figures Switzerland 72/450 Patented Jan. 7, 1975 1.6 Sheets-Sheet 1 Patented Jan. 7, 1975 3 ,858,432

16 Sheets-Sheet 2 Patented Jan. 7, 19-75 Patented Jan. 7 1975 16 Sheets-Sheet 1O atented Jan. 7, 1975 3,858,432

1,6 Sheets-Sheet 11 atented J. 7, 1975 3v858432 16 Sheets-Sheet 15 I STROKE COMMAND VOLTAGE (EDDY CUQRENT CONTQOL) START I NORMAL. ILONCD Loop OR TIME- F I G. 23

Patented Jan. 7, 1975 16 Sheets-Sheet 15 Patented Jan. 7, 1975 16 Sheets-Sheet l6 zod nwwm m PRESS STRUCTURE The present invention relates to mechanical presses and is particularly concerned with a mechanical press which operates at extremely high speed.

Mechanical presses are, of course, well known and consist of a frame with a crankshaft which is driven by a motor and to which crankshaft is connected a slide that reciprocates in the press to and from a bed member with parts of a die set being mounted on the slide and bed member for operating workpieces inserted therebetween as the slide reciprocates.

Mechanical presses are widely used for blanking and drawing operations and vary substantially in size and available tonnage and in the various accessories associated therewith.

It is usually the case that the slide in a mechanical press is connected to the crankshaft by a connecting rod which is adjustable in length or which is connected to another member that is adjustable in its relation to the slide so that the daylight opening between the slide and the bed can be adjusted to accommodate the press for various die sets. The slide is usually guided on the upright portions of the press frame extending between the head and bed so that the parts of the die set remain in accurate registration as the slide reciprocates.

The pressaccording to the present invention is particularly characterized in being capable of extremely high speed operation, up to 1,600 strokes per minute or more of the press slide in a press rated at 60 tons or more. The press according to the present invention is, thus, particularly useful for blanking operations, such as for electric motor laminations and the like and, in contrast to high speed presses that are presently available, has a relatively long stroke and operates relatively large workpieces by virtue of the unique design of its bearings, reciprocating members, and stock feeding apparatus.

A particular object of the present invention is the provision of a mechanical press so constructed and arranged as to permit operation thereof within the range of speeds above referred to, namely, up to 1,600 strokes a minute or'more.

Another object of the present invention is the provision of a slide construction and arrangement which permits high speed operation of the slide.

Still another object is the provision of a mechanical press especially constructed for high speed operation in which all of the relatively moving parts of the press are adequately lubricated at all times and wherein the undesirable heat developed from the high speed operation of the press rapidly conveyed from the bearings and dissipated.

Still another object of the present invention is the provision of a mechanical press in which the daylight opening of the press can be adjusted but in which the adjusting arrangement for this purpose is separated from the slide of the press so as not to add any additional weight thereto.

Still another object of the present invention is the provision of a novel guide arrangement for guiding the slide of a mechanical press.

Still another object of the present invention is the provision of a mechanical press in which dual counterrotating crankshafts are employed for actuating the press slide with a dynamic balancing arrangement provided for inhibiting vibration of the press at high speed.

These and other objects and advantages of the present invention. will become more apparent upon reference to the following detailed specification taken in connection with the accompanying drawings in which:

FIG. 1 is an exploded perspective view of the press frame.

FIG. 2 shows a stock supply and a straightening roll stand through which the stock is fed toward the press and also shows the extreme left end of a stock loop control device.

FIG. 3 is a perspective view showing a press according to the present invention and showing the right end of the stock loop control device referred to in respect of FIG. 2.

FIG. 4 is a view partly in section showing the head of the press and looking in at the press in the same direction as in FIG. 3.

FIG. 5 is a view like FIG. 4 but looking in at the head of the press from the rear of FIG. 3 and with the cover plate removed from the press head to expose the parts therein. I

FIG. 6 is a somewhat schematic plan sectional view indicated by line 6-6 on FIG. 4 and showing passages for cooling air provided in the press head.

FIG. 7 is a fragmentary vertical sectional view through one of the crankshafts of the press and is indicated by line 7-7 on FIG. 4.

FIG. 8 is a somewhat schematic vertical sectional view indicated substantially by line 8-8 on FIG. 7.

FIG. 9 is a sectional view indicated by line 9-9 on FIG. 8.

FIG.v 10 is a fragmentary perspective view showing the manner in which hydrostatic bearing pockets are formed in the sleeve member illustrated in FIG. 9.

FIGS. 11A and 11B are somewhat schematic views showing the manner in which hydrostatic bearing pockets are formed in the crankshafts.

FIG. 12 is a section on line 12-12 of FIG. 11.

FIG. 13 is a section on line 13-13 of FIG. 11.

FIG. 14 is a sectional view indicated by line 13-13 on FIG. 11 showing a groove establishing a hydrostatic thrust bearing for the crankshaft.

FIG. 15 shows a typical flow restrictor which is disposed at the entrance of each hydrostatic bearing pocket to control the oil flow thereto.

FIG. 16 is a perspective view illustrating the manner in which the bed member that receives the stationary portion of the die set is adjustably mounted in the press.

FIG. 17 is a sectional view indicated by line 17-17 on FIG. 16 showing a fluid actuator connected with the. adjustable bed member to assist in the elevation thereof and to clamp the bed member in adjusted positions.

FIG. 18 is a sectional View indicated by line 18-18 on FIG. 16 showing one of the adjusting devices for adjusting the bed member in the press frame.

FIG. 19 is a fragmentary plan sectional view looking down on top of the bed member and showing the manner in which it is clamped in the press frame in adjusted positions.

FIG. 20 is a fragmentary perspective view showing the fluid actuators which clamp the adjustable bed member in the press frame. I I

FIG. 21 is a schematic view showing the straightening roll stand and the drive thereto and the loop control device to which the straightening roll stand feeds the stock being operated.

FIG. 22 schematically illustrates the control pulses developed for controlling the speed of operation of the straightening roll stand.

FIG. 23 schematically illustrates the hydraulic circuit of a stock feed arrangement interposed between the loop control device and the die set in the press for feeding stock into the die set.

FIG. 24 is a vertical sectional view through the feed device.

FIG. 25 is a plan section indicated by section line 25-25 on FIG. 24 showing an intermittent feed arrangement for intermittently driving the feed rolls of the feed device.

FIG. 26 is a section indicated by line 26-26 on FIG. 25 showing more in detail the intermittent feed and an arrangement for eliminating lost motion therein.

FIG. 27 is a schematic representation of the hydraulic control circuit employed with the press.

' tion has a press frame consisting of a bed portion and a sealed crown portion and uprights extending therebetween with prestressing strain rods interconnecting the crown portion and bed portion.

Within the crown portion is rotatably mounted a pair of counterrotating crankshafts, each having a throw thereon to which one end of a connecting rod is connected. Each connecting rod at the other end is connected with one end of a piston member with the other end of each piston member being connected to the press slide that is disposed beneath the crown portion of the press frame.

The press crown includes cylinders which are open at both ends and in which the aforementioned pistons are slidably guided. Balancing weights mounted on the crankshaft substantially counterbalance the slide and pistons and connecting rods so that the press will operate at high speed without any substantial amount of vibration.

The aforementioned crankshafts are geared together at one end and the other end of the crankshafts is connected to a flywheel through a pneumatically operated clutch. The flywheel is belt-driven from a drive motor that may be variable in speed or which may have a variable speed output shaft which is drivingly connected with the motor by way of an eddy-current clutch.

The other crankshaft has a brake disc mounted thereon adjacent the aforementioned clutch and flywheel for braking the crankshaft to a halt when necessary. When the aforementioned clutch disengages the crankshaft from the flywheel the minimum amount of energy is presented to the brake which must bring the crankshafts and the parts connected thereto to a halt.

The flywheel also has a brake associated therewith which is not, however, employed during normal press operations, but is merely used during set up and to bring the flywheel quickly to a halt when necessary.

The bed portion of the press has a vertically adjustable bed member therein so that the daylight opening of the press can be adjusted without providing adjustable members associated with the connecting rods and which would add to the reciprocating mass.

The adjustable bed member is adapted for being elevated and lowered by screw jacks disposed therebeneath and is clamped fixedly in position by fluid actuators engaging the bed member from above and which fluid actuators are also employed to carry the weight of the bed member during vertical adjustment thereof.

The press is arranged to operate at extremely high speed, up to 1,600 strokes per minute or more, and an arrangement for feeding strip stock to the press is provided which will feed efficiently at the operating speeds referred to.

The stock supply is preferably in the form of a roll, or reel, of strip stock rotatably supported and a drag brake is provided to maintain tension on the stock and to prevent the stock reel from running ahead when the press is stopped. The stock from the stock reel leads to a straightening roller stand which is driven at variable speed as by way of an eddy current clutch. The stock, upon leaving the straightening roll stand, passes through an enclosure which guides the stock and within which the stock is thrown into somewhat of an S- shaped loop.

Within the enclosure, detectors are provided which detect maximum and minimum lengths of the loop therein. When a maximum length is detected, the speed of the straightening roller, stand is reduced and when a minimum loop is detected the press and the straightening roller stand are halted. The straightening roller stand is arranged to feed' a slight excess amount over the feed required by the press on each stroke, so that the maximum loop detector, in normal operation, will periodically reduce the feed from the straightening roller stand.

Between the straightening roller stand and the press is a feed arrangement consisting of opposed rollers which bear on the stock from opposite sides and one of which is intermittently driven so as to advance stock into the die set in the press while the die set is open. The feed device includes an arrangement for eliminating lost motion in the drive to the feed rolls so that the feed into the die set in the press is quite rapid and without hesitation and is substantially positive. The feed device comprises an arrangement for separating the rolls under emergency conditions and also when the rotation of the driven one of the rollers is interrupted.

Due to the high speed of operation of the press, it is preferable for the relatively moving parts continuously ticularly for the rapid moving parts of the press, the

crankshaft and the connecting rods and the pistons connected to the slide are provided with hydrostatic bearing arrangements to which lubricating fluid is continuously supplied at controlled pressure.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings more in detail, the press frame has a crown portion 50 and a lower frame portion 48 and uprights 52 therebetween. The lower frameportion 48 of thepress frame and the uprights 52 may be combined in the form of integral frame members 53 in front and 55 in back, each having a window 600 therein. Frame member 53 engages the underneath side of the crown 50 at thr front of the press and frame member 55 engages the underneath side of the crown 50 at the back of the press. Leg members 54 and 56 extend in the fore and aft direction of the press beneath the lower ends of the above mentioned frame members 53 and 55 and at the opposite sides of the frame members are the bed clamp beam members 602 extending in the fore and aft direction of the press.

The crown and frame members and leg members are fixedly interconnected by prestressed strain rods 47 extending vertically therethrough and disposed near the corners of the crown portion 50 of the press frame. Nuts 59 are threaded on the ends of rods 57.

The bed clamp beam members 602 are bolted to the frame members 53 and 55 and the frame members together with the above mentioned bed clamp beam members define the space in which the bedmember of the press, indicated at 46, is disposed for vertical adjustability.

In FIG. 2, numeral 30 generally'designates a stock supply which may take the form of a reel of strip stock 32 mounted on a rotary support with the support preferably including a drag brake to stabilize rotation of the reel. From the stock supply, stock 32 is delivered to a straightening roller stand generally designated at 34 and which is substantially conventional except for the drive thereto which will be discussed more fully hereinafter.

Within the straightening roller stand, the stock passes through spaced sets of feed rollers which advance the stock in the direction of its length and interposed between the feed rollers are a plurality of straightening rollers in opposed rows and staggered relation so that the stock is straightened as it passes through the straightening roller stand. From the straightening roller stand, the stock enters a stock loop control device generally indicated at 36 and also to be discussed more fully hereinafter. i

In brief, within the stock control device, the strip of stock is thrown into a generally S-shaped curve and within the stock control device are instrumentalities for detecting a predetermined maximum length of the loop and a predetermined minimum length. thereof. The straightening roller stand is arranged to feed stock at a slightly higher speed than it is consumed in the press so that, under normal circumstances, the stock loop gradually lengthens 'until a detector in the device detects a maximum loop length whereupon the speed of feeding stock through the straightening roller stand is reduced to reduce the length of the loop and normal feeding operations then continue. When a minimum stock loop is detected, a situation that should not occur in normal operation, the operation of the press and the straightening roller stand is stopped.

FIG. 3 will show that the loop detecting device is connected to supply the stock to a feed device, generally indicated at 38 and which feeds the stock into the press. Device 38 feeds the stock intermittently, interrupting the feed during the working stroke of the press when the die set therein closes and feeding stock when the die set is open. The strip of stock being fed into the press is confined from above, as by a plate 40, and under emergency conditions when the stock jams or the feeding thereof into the die set is otherwise interrupted, the stock will buckle downwardly and actuate 6 a switch which will interrupt the feeding of the stock and stop the press.

Within the press is a die set consisting of an upper part 42 and a lower part 44. Lower part 44 is mounted on a bolster 45 supported on a bed member 46 which is vertically adjustable between the lower bed portions of the front and rear press frame members 53 and 55. The press frame includes crown portion 50, front and rear press frame members 53 and 55 with lower portion 48 integral with vertical portions 52 extending between the crown portion and the legs 54 and 56.

The press frame is supported on a leg 54 having two feet at one side of the press and leg 56 having one foot at the other side so that the press can be more easily mounted on a nonuniform surface.

The upper portion 42 of the die set is mounted on a slide 58 that is driven in reciprocation in the space between crown portion 50 and bed portion 46 by crankshaft means rotatably mounted in the crown portion. The crankshaft means receives power from a drive motor 60 which is either variable in speed or which drives the crankshaft means through an eddy current clutch so that the speed of the crankshaft means can be.

controlled.

The press according to the present invention is adapted to operate at extremely high speeds, up to 1,600 strokes per minute or more, and considerable heat may be developed in at least the crown portion of press frame and out the stack 66. As will be seen hereinafter, the air is blown through a heat exchange interposed between blower 62 and the air passages in the crown-portion of the press.

The skeleton of the stock fed out. of the die set passes through a scrap cutter 68 arranged at the side of the press opposite the feed device 38 so that the skeleton of stock is clipped into small pieces as it emerges from the press so that it is in ideal form for disposal as scrap.

The entire operation of the press may be controlled from a console 70 suitably positioned adjacent the press and connected by cable means with a relay panel 72.

The above mentioned crankshaft means mounted in the press crown comprise a pair of counterrotating crankshafts (FIG. 4) which extend in the fore and aft direction of the press crown, namely, in a direction at right angles to the direction ofstock fed through the press, which is considered from side to side.

FIG. 4 shows at somewhat enlarged scale the crown of the press looking in the same direction as in FIG. 3 but with portions of the crown cut away to show the interior thereof. In FIG. 4, the crankshafts of the press are seen from one end and are indicated at 74 and 76. The crankshafts, on the ends visible in FIG. 4, carry gears 78 and 80, respectively, which mesh and which cause counterrotation of .the crankshafts in synchronism. Gears 78 and 80 are disposed in a recessed compartment 82 in the crown portion 50 ofthe press and which is normally closed by a cover plate 84. The gears have holes 79 and 81 therein for counterbalancing purposes to be explained more fully hereinafter.

FIG. 4 also shows blower 62 and drive motor 64 therefor and, in FIG. 4, it will be seen that the blower 62 has an inlet 86 and an outlet discharging througha 

1. In a mechanical press having a frame with a bed portion and a crown portion and a frame interconnecting said portions and a slide reciprocable in the space between said crown and bed portions; crankshaft means rotatably mounted in said crown portion, connecting rod means connected at one end to said crankshaft means, piston means connected at one end to the other end of said connecting rod means and at the other end to said slide, cylinder means parallel to the direction of movement of said slide including hydrostatic bearing means surrounding and slidably engaging said piston means for centering said piston means within said cylinder means.
 2. A mechanical press according to claim 1 which includes journal portions on said crankshaft means, bearings in said crown portion engaging said journal portions, and hydrostatic bearing means interposed between said journal portions and said bearings.
 3. In a mechanical press having a frame with a bed portion and a crown portion and a frame interconnecting said portions and a slide reciprocable in the space between said crown and bed portions; crankshaft means rotatably mounted in said crown portion, connecting rod means connected at one end to said crankshaft means, piston means connected at one end to the other end of said connecting rod means and at the other end to said slide, cylinder means parallel to the direction of movement of said slide surrounding and slidably engaging said piston means, said crankshaft means comprising a pair of parallel crankshafts, a gear on each crankshaft, said gears meshing and connecting said crankshafts for counterrotation, said connecting rod means comprising a connecting rod connected to eAch crankshaft, said piston means and cylinder means comprising a piston and cylinder for each connecting rod, and balancing means located on said crankshafts for substantially counterbalancing the mass of the slide and pistons and connecting rods.
 4. A mechanical press according to claim 3 which includes air passage means in said crown portion, and means for blowing air through said air passage means.
 5. A mechanical press according to claim 3 which includes passage means in said crown portion extending perpendicular to and around said cylinder means, a blower for supplying air to one end of said passage means.
 6. A mechanical press according to claim 1 in which said cylinder means include annular regions at each end in continuous sliding engagement with said piston means, pockets formed in said regions and distributed circumferentially thereof, and means for supplying fluid at controlled pressure to said pockets.
 7. A mechanical press according to claim 1 in which said crankshaft means comprises journal portions, bearings in said crown portion engaging said journal portions, pockets formed in said journal portions and distributed circumferentially thereof, and passage means in said crankshaft connected to said pockets for the supply thereto of fluid at controlled pressure.
 8. In a mechanical press having a frame with a bed portion and a crown portion and a frame interconnecting said portions and a slide reciprocable in the space between said crown and bed portions; crankshaft means rotatably mounted in said crown portion, said crankshaft means adapted to reciprocate said slide, said crankshaft means including journal portions, bearings in said crown portion engaging said journal portions, pockets formed in said journal portions and distributed circumferentially thereof, and passage means including a flow restrictor disposed in each passage in said crankshaft connected to said pockets for the supply thereto of fluid at controlled pressure.
 9. A mechanical press according to claim 8 in which crankshaft includes crankpin means engaging said connecting rod means, and further pockets formed in said crankpin means and connected to said passage means to receive fluid at controlled pressure therefrom.
 10. A mechanical press according to claim 3 in which said balancing means comprises at least one eccentric mass on each crankshaft and eccentric mass incorporated in said gears.
 11. A mechanical press according to claim 3 in which said gears are fixed to said crankshafts at one end thereof, a flywheel-clutch on the other end of one crankshaft adapted for being driven to supply power to said crankshafts, and brake means interposed between said frame and the other end of the other crankshaft selectively operable for braking said crankshafts to said frame.
 12. A mechanical press according to claim 11 in which said brake means includes a disc fixed to said other end of said other crankshaft, and caliper brake means on said frame adjacent said disc.
 13. A mechanical press according to claim 12 in which said caliper brake means include first caliper brake means operable into braking engagement with said disc by fluid pressure and second caliper brake means spring urged toward braking engagement with said disc and operable into retracted position by fluid pressure.
 14. In a mechanical press having a frame with an adjustable bed portion and a crown portion and a frame interconnecting said portions and a slide reciprocable in the space between said crown and said bed portion, said bed portion being adjustable in a direction toward and away from said slide for providing the correct shut height for a die set, said bed member being mounted in the lower portion of said frame, first means adjustably supporting said bed member in the lower portion for movement of the bed member toward and away from the crown portion, fluid means in the lower portion for fixedly clamping said bed member in adjusted vertical position additional fluid means for fixedly clamping said beD member in a plane parallel to its surface, crankshaft means rotatably mounted in said crown portion, connecting rod means connected at one end to said crankshaft means, piston means connected at one end to the other end of said connecting rod means and at the other end to said slide, and cylinder means parallel to the direction of movement of said slide surrounding and slidably engaging said piston means.
 15. A mechanical press according to claim 14 in which said first means include screw threaded means interposed between the underside of said bed member and the lower portion.
 16. A mechanical press according to claim 14 in which said first means includes cylinder piston means above said bed member and connected between spaced points of said bed member and the press frame and operable in one condition of energization to exert upward force on said bed member and in another condition of energization to exert downward force on said bed member.
 17. A mechanical press according to claim 14 in which said second means including V-shaped members on opposite sides of said bed member extending in a direction parallel to the direction of adjustability of the bed member, a first member fixed to the lower portion of the press frame at one side of the bed member complementary in shape to and engaging the adjacent V-shaped member, a second member movably mounted on the lower portion of the press frame at the other side of the bed member complementary in shape to and engaging the adjacent V-shaped member, and actuator means in said lower portion engaging said second member on the side facing away from the said bed member and operable by the supply of pressure fluid thereto to clamp said bed member to said lower portion.
 18. In a press having spaced and fixedly interconnected crown and lower portions, a bed member, adjustable toward and away from said crown portion, means in said lower portion operable to clamp and locate said bed member therein, crankshaft means rotatable in said crown portion, piston means slidably guided in elongated cylinders in said crown portion for movement toward and away from said bed member, means operatively connecting said crankshaft means to said piston means, and a slide connected to said piston means at the end thereof nearest said bed member, said piston means forming the sole means supporting and guiding said slide in said press frame.
 19. A press according to claim 18 in which said crown portion is a box-like member having a sealed compartment within which said crankshaft means is supported.
 20. In a press having a press frame with spaced crown and lower portions, said frame having a front and a back and sides, a slide in the space between said crown and lower portions, a pair of parallel crankshafts rotatable in said crown portion and extending in the fore and aft direction therein, an elongated cylinder in the crown portion beneath the throw of each crankshaft, said cylinders being in parallel aligned relation in the side to side direction of said crown portion, a piston slidable in each cylinder and at the bottom fixed to said slide, said pistons and cylinders providing the sole support and guidance of said slide, and a connecting rod connected between the throw of each crankshaft and the upper end of the said piston therebeneath.
 21. A press according to claim 20 which includes gears on one end of the crankshafts in direct meshing relation for synchronous rotation of the crankshafts in respective opposite directions.
 22. A press according to claim 20 which includes counterweight means fixed to each crankshaft on the opposite side of the throw thereof from the end of the crankshaft on which a said gear is mounted, each said gear comprising eccentric mass having the same angular disposition about the axis of the crankshaft as said counterweight means.
 23. In a press according to claim 20, said frame having lower portion at the bottom, base means beneath said lower portion to support the press frame on a floor surfAce, said base means having two spaced leg means at one side of the press and a single leg means at the other side of the press thereby providing substantially three point support for the press frame so that a portion of the press weight is supported on each leg irrespective of the waviness of the floor.
 24. In a press frame; a press crown, spaced frame members extending from side to side of the press and engaging the underside of said crown at the front and back of the crown, each frame member being windowed to expose the space beneath said crown, base members extending in the fore and aft direction of the press frame and engaging the underside of said frame members at the ends thereof, and strain rods extending vertically through said crown and frame members and base member and fixedly interconnecting said crown and frame members and base members.
 25. A press frame according to claim 24 which includes beam members extending in the fore and aft direction of the press frame at the sides of said frame members near the lower ends thereof and fixed to said frame members.
 26. A press frame according to claim 25 which includes a bed member disposed in the space confined in the fore and aft direction by said frame members and in the side to side direction by said beam members.
 27. A press frame according to claim 24 which includes means in said crown for rotatably supporting crankshafts therein extending in the fore and aft direction of the press frame, compartments recessed into the front and rear sides of the crown in which the ends of the crankshafts are disposed, and cover plates enclosing said compartments.
 28. A press frame according to claim 24 in which one base member has a pair of dependent foot portions each at a respective end of the base member and the other base member has a single dependent foot portion near the middle of the length thereof.
 29. A press frame according to claim 26 which includes bed member adjusting means interposed between said bed member and said base members.
 30. A press frame according to claim 29 which includes reversible fluid actuators connected between the corners of said bed member and the underside of said crown.
 31. A press frame according to claim 29 which includes clamping means carried by said bed member and said beam members operable for fixedly clamping said bed member in adjusted positions in said press frame.
 32. In a crown for a press frame; a generally vertical body having body front and back faces and end faces and top and bottom faces, chambers recessed into said end faces and cover plates closing said chambers toward the outside, finned passage means extending laterally of said body and connected to said chambers near the bottoms thereof, a blower connected to one chamber near the top thereof, and an exhaust conduit connected to the other said chamber near the top.
 33. A crown according to claim 32 which includes heat exchanger means in said one chamber through which air is blown by said blower.
 34. A crown according to claim 32 in which said finned passage means are open at the front and back faces of said body, and further cover plates on the front and back faces of said body closing off said passage means from the atmosphere.
 35. A crown according to claim 32 which includes means in said body defining vertical cylinders extending therein from said bottom face and passing through said finned passage means in substantial perpendicular relation thereto. 